Reels or carousels: what works for a business on Instagram

In October 2024 Adam Mosseri, the head of Instagram, posted a video on his account explaining why carousels often get better results than single photos. One of the two reasons was a detail almost nobody notices while scrolling: when someone sees a carousel and doesn't swipe through it, Instagram often gives that carousel a second chance, and it is shown to them again, this time opening on the second image. That is how the Italian news agency AGI reported it on October 18, 2024.

In other words, a carousel has two covers. A reel has only one, and if it doesn't stop the thumb in the first second, the moment is gone. That alone shows that the question “reels or carousels?” is asking us to compare two things that do different jobs.

What do the numbers say about reels and carousels?

The two most cited studies on the subject reach conclusions that don't line up.

Buffer, which makes a tool for publishing on social media, analyzed more than 4 million posts published between January 2022 and October 2024. The result: reels reach 36% more people than carousels on average, while carousels get 12% more interactions than reels (likes, comments, saves and shares). The single photo loses on both counts.

Socialinsider looked at 35 million posts from 447,613 accounts active in 2025. On interactions, carousels are slightly ahead: an average rate of 0.55% per post against 0.52% for reels, with single photos stuck at 0.37%. On average views, though, the surprise is something else: carousels beat reels in every follower range. For an account with 10,000 to 50,000 followers, that means 4,275 average views for a carousel against 2,460 for a reel.

Why do two studies this large disagree?

Because they measure different things, in different years, on different accounts. Buffer counts the people reached and uses data from people who publish with its tool, up to 2024. Socialinsider counts average views, on a much larger sample and with 2025 data. In the meantime Instagram changed its rules several times.

The useful point for a business is that both are averages. They include shops, influencers, soccer teams, newspapers. An average across hundreds of thousands of accounts tells you what happens in general and almost nothing about what will happen to the account of a car repair shop in Bergamo or a furniture maker in Brianza. Choosing a format by looking only at those numbers means copying someone else's behavior.

What does a reel do that a carousel doesn't?

The reel is the format Instagram uses to bring content to people who don't follow an account yet. A feature introduced in December 2024 shows this clearly: trial reels. Anyone with at least 1,000 followers and a public account can post a reel that is shown at first only to people who don't follow them. After about 24 hours they see how it did and decide whether to show it to their own followers too.

Since January 2025, a reel can also run up to 3 minutes, compared with 90 seconds before. This opens room for longer stories, but it doesn't change the rule of the first few seconds: a video that doesn't hold viewers right away gets shown to fewer people. In January 2025 Mosseri named watch time as one of the three signals that carry the most weight, along with likes and private sends.

For a business, then, the reel is the tool for getting found by people who don't know it exists today. It works when it shows something you understand with your eyes: a product that goes together in ten seconds, a before-and-after of a job, a person explaining a mistake customers make without realizing it.

What does a carousel do that a reel doesn't?

A carousel is read at your own pace. Whoever opens it can stop on a slide, go back, save it for later. Socialinsider confirms this: carousels are the format that collects the most saves. Since August 2024 they can hold up to 20 photos and videos, twice as many as before.

It is the right format when something needs explaining that would go too fast out loud: a comparison between two solutions, the steps of a job, the numbers of a case. And because of the second cover Mosseri talked about, slide two matters almost as much as the first: it has to stand on its own, because for some people it will be their first contact with the post.

So what should a business choose?

Our reading, as a Category Design agency, is that the choice of format comes after another decision: what specific thing the business wants to be remembered for. If that isn't clear, reels and carousels become two different ways of saying nothing, and the account ends up looking like its competitors'. If it is clear, the format is chosen post by post, based on the job.

• Getting discovered by people who don't know the business: a reel, short, with the strongest thing in the first few seconds.
• Explaining why the business works differently: a carousel, one idea per slide, with the second slide built as a second cover.
• Being remembered: both, repeating the same idea with different words and images until people link it to the business without thinking.

On Project Mantra's account we use the two formats this way: the reels tell in one minute how a brand won or lost its game, the carousels take a case apart slide by slide. The underlying message is the same; what changes is the job each post does. Anyone who wants to understand where that message starts will find the method in the guide to Category Design.

To judge the results, the numbers to watch are the ones Mosseri pointed to in January 2025: average watch time, likes per reach, sends per reach. They should be compared across posts on the same account, not against the averages in the studies.

What mistakes do businesses make most often with the two formats?

The first is turning the carousel into a flyer: ten slides of catalog, the logo on every one and no reason to reach the third. The second is using the reel like a cut-down TV commercial, with the brand showing up at the start and the substance at the end, when the viewer has already scrolled away.

The third is choosing the format because it's fashionable, convinced that switching is enough to grow. When an account is small, the format matters less than people think. In Socialinsider's table for accounts with 1,000 to 5,000 followers, the average number of saves per post is 1 for reels, 1 for carousels and 1 for single photos.